The microtype package

THE TITLE LOGO: Macros 214\printbbss\printbb\showboxes8819 \fi8820 #2%8821 }Loop over all characters of the string.8822 \def\printbbss#1#2#3\relax{%8823 \ifx\relax#1\relax8824 \else8825 \ifx\relax#2\relax8826 \printbb{#1}{}%8827 \else8828 \printbb{#1}{#2}%8829 \fi8830 \expandafter\printbbss8831 \fi8832 #2#3\relax8833 }Record the kern between the current and the following character, then print the character. \kerning is a fontinstcommand.8834 \setcommand\printbb#1#2{%8835 \setbox0\hbox{\kerning{#1}{#2}\xdef\thekern{\number\result}}%8836 \showboxes{#1}%This could be another application.8837 % \quad8838 % w: \the\scaletoem{\width{#1}},8839 % bb: \the\scaletoem{\bbleft{#1}}/%8840 % \the\scaletoem{\bbright{#1}},8841 % \the\scaletoem{\number\numexpr\width{#1}-\bbright{#1}\relax}8842 % h: \height{#1}/\bbtop{#1}, \bbbottom{#1}/\depth{#1}\par8843 }Print the boxes for character 〈#1〉. This will not work if 〈#1〉 is not also the PostScript name of the glyph (e.g., ‘comma’=/ ‘,’).8844 \setcommand\showboxes#1{%8845 \leavevmode8846 \color{texcolor}%We have to record the width of the glyph.8847 \setbox0\hbox{{\color{textcolor}#1}}%8848 \global\tempdim=\wd0\relax8849 \kern-\fboxrulei1. The TEX box: Print a frame in color texcolor. This frame shows the glyph as TEX sees it.8850 \mtl@layer{TeX-boxes}{%8851 \hbox{%8852 \lower\dimexpr \dp0 + \fboxrulei\relax8853 \hbox{%8854 \vbox{%8855 \hrule height\fboxrulei8856 \hbox{%8857 \vrule width\fboxrulei height \dimexpr\ht0 + 2\fboxrulei\relax8858 \phantom{\unhcopy0}%8859 \vrule width\fboxrulei8860 }%8861 \hrule height\fboxrulei}}}%8862 }%2. The character: Now we step back and print the actual glyph. We hold it back until now, so that it will be printedon top of its box.8863 \kern-\wd08864 \mtl@layer{characters}{%8865 \hbox{\box0}%8866 }%Step back by the amount that the character’s bounding box differs from the TEX box on the left side.8867 \kern\dimexpr\scaletoem{\bbleft{#1}}-\tempdim-\fboxruleii\relax